Trenton Oldfield with his pregnant wife Deepa. 'People with whom we disagree are the best test of the fairness of our legal system.'
Photograph: Felix Clay

When Trenton Oldfield swam out in front of the Oxford and Cambridge boats in the 2012 Boat Race, it brought it to an abrupt halt. Four years earlier, I had raced down the same course in the 2008 Cambridge crew, from Putney to Mortlake, as the culmination of two years of training 11 times a week, for 50 weeks of the year. Although in many other settings I could be convinced by an act of principled protest, on home turf, my main reaction was of anger at this act of sabotage, which cruelly robbed both crews of a fair resolution to this increasingly tight race and to their months of training.

If the sabotage of the race was what I felt most viscerally, for Oldfield that was mere collateral. His real intention was to spark a debate. After some initial prevarication on his reasons – a rambling essay about gas chambers and colonialism preceded the explanation "I would have felt less of a man if I hadn't done it" – a recent interview suggests he has settled on "elitism" as the target of his intervention. When he told the Guardian that 500,000 people had Googled the word that day, the triumphant implication was that he had succeeded in sparking that debate.

Belatedly, I'd like to take him up on the invitation. To outsiders, the Boat Race may have looked like an over-hyped coin toss, but in reality it was not the best target for Oldfield to make his point. Unlike the roving caravan of international brands and gagging clauses taking place behind a perimeter wall in Stratford that summer, the rowing event is completely free to the hundreds of thousands of people who come to watch it each year. In recent years, the university boat clubs have been forced to allow sponsorship to creep in to cover the cost of closing the river for the day, but this has enabled the event to remain unticketed, and avoids the need for any government subsidy. The Boat Race is an amateur event; there is no prize beyond winning. Taking place on the same stretch of river every year, it has minimal environmental impact, and means a lot to the Londoners who line the route every spring.

Originally from Australia, Oldfield has lived in the UK for more than 10 years and is married to a British citizen with whom he is due to have a child. The Home Office has said his presence in the country would not be "conducive to the public good". He is appealing against the Home Office's decision, on the grounds that it should have considered article 8 of the European convention on human rights, which guarantees the right to a family life. He has now found himself swept up in another, much larger debate, about the politicisation of legal sanctions.

The principles of human rights should apply to everyone. The Human Rights Act enshrines those principles in UK law, providing protection against the anger and changeability of public opinion, or a home secretary too prone to pander to its excesses. That we apply these principles equally to those with whom we fundamentally disagree, is the proof of our commitment to them.

I know what each of the participants of that race committed to when they stepped into those boats, and I share in their anger at Oldfield. But these things are more important than a race. People with whom we disagree are the best test of the fairness of our legal system. When asked to comment on the matter, a Home Office spokesman said, "those who come to the UK must abide by our laws". They ought to be protected by them too.